5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Copyright 2000,2001,2002 The FreeRADIUS server project
20 * Copyright 2001,2002 Google, Inc.
21 * Copyright 2005 TRI-D Systems, Inc.
25 * STRONG WARNING SECTION:
27 * ANSI X9.9 has been withdrawn as a standard, due to the weakness of DES.
28 * An attacker can learn the token's secret by observing two
29 * challenge/response pairs. See ANSI document X9 TG-24-1999
30 * <URL:http://www.x9.org/docs/TG24_1999.pdf>.
32 * Please read the accompanying docs.
36 * TODO: support setting multiple auth-types in authorize()
37 * TODO: support other than ILP32 (for State)
43 #include <sys/types.h>
48 #include <netinet/in.h> /* htonl(), ntohl() */
55 static const char rcsid[] = "$Id$";
58 static unsigned char hmac_key[16]; /* to protect State attribute */
59 static int ninstance = 0; /* #instances, for global init */
61 /* A mapping of configuration file names to internal variables. */
62 static const CONF_PARSER module_config[] = {
63 { "pwdfile", PW_TYPE_STRING_PTR, offsetof(otp_option_t, pwdfile),
65 { "lsmd_rp", PW_TYPE_STRING_PTR, offsetof(otp_option_t, lsmd_rp),
67 { "challenge_prompt", PW_TYPE_STRING_PTR,offsetof(otp_option_t, chal_prompt),
68 NULL, OTP_CHALLENGE_PROMPT },
69 { "challenge_length", PW_TYPE_INTEGER, offsetof(otp_option_t, chal_len),
71 { "challenge_delay", PW_TYPE_INTEGER, offsetof(otp_option_t, chal_delay),
73 { "softfail", PW_TYPE_INTEGER, offsetof(otp_option_t, softfail),
75 { "hardfail", PW_TYPE_INTEGER, offsetof(otp_option_t, hardfail),
77 { "allow_sync", PW_TYPE_BOOLEAN, offsetof(otp_option_t, allow_sync),
79 { "fast_sync", PW_TYPE_BOOLEAN, offsetof(otp_option_t, fast_sync),
81 { "allow_async", PW_TYPE_BOOLEAN, offsetof(otp_option_t, allow_async),
83 { "challenge_req", PW_TYPE_STRING_PTR, offsetof(otp_option_t, chal_req),
84 NULL, OTP_CHALLENGE_REQ },
85 { "resync_req", PW_TYPE_STRING_PTR, offsetof(otp_option_t, resync_req),
86 NULL, OTP_RESYNC_REQ },
87 { "prepend_pin", PW_TYPE_BOOLEAN, offsetof(otp_option_t, prepend_pin),
89 { "ewindow_size", PW_TYPE_INTEGER, offsetof(otp_option_t, ewindow_size),
91 { "rwindow_size", PW_TYPE_INTEGER, offsetof(otp_option_t, rwindow_size),
93 { "rwindow_delay", PW_TYPE_INTEGER, offsetof(otp_option_t, rwindow_delay),
95 { "mschapv2_mppe", PW_TYPE_INTEGER,
96 offsetof(otp_option_t, mschapv2_mppe_policy), NULL, "2" },
97 { "mschapv2_mppe_bits", PW_TYPE_INTEGER,
98 offsetof(otp_option_t, mschapv2_mppe_types), NULL, "2" },
99 { "mschap_mppe", PW_TYPE_INTEGER,
100 offsetof(otp_option_t, mschap_mppe_policy), NULL, "2" },
101 { "mschap_mppe_bits", PW_TYPE_INTEGER,
102 offsetof(otp_option_t, mschap_mppe_types), NULL, "2" },
104 { "twindow_min", PW_TYPE_INTEGER, offsetof(otp_option_t, twindow_min),
106 { "twindow_max", PW_TYPE_INTEGER, offsetof(otp_option_t, twindow_max),
110 { NULL, -1, 0, NULL, NULL } /* end the list */
114 /* transform otp_pw_valid() return code into an rlm return code */
119 case OTP_RC_OK: return RLM_MODULE_OK;
120 case OTP_RC_USER_UNKNOWN: return RLM_MODULE_REJECT;
121 case OTP_RC_AUTHINFO_UNAVAIL: return RLM_MODULE_REJECT;
122 case OTP_RC_AUTH_ERR: return RLM_MODULE_REJECT;
123 case OTP_RC_MAXTRIES: return RLM_MODULE_USERLOCK;
124 case OTP_RC_SERVICE_ERR: return RLM_MODULE_FAIL;
125 default: return RLM_MODULE_FAIL;
130 /* per-instance initialization */
132 otp_instantiate(CONF_SECTION *conf, void **instance)
137 /* Set up a storage area for instance data. */
138 opt = rad_malloc(sizeof(*opt));
139 (void) memset(opt, 0, sizeof(*opt));
141 /* If the configuration parameters can't be parsed, then fail. */
142 if (cf_section_parse(conf, opt, module_config) < 0) {
147 /* Onetime initialization. */
149 /* Generate a random key, used to protect the State attribute. */
150 if (otp_get_random(-1, hmac_key, sizeof(hmac_key)) == -1) {
151 otp_log(OTP_LOG_ERR, "failed to obtain random data for hmac_key");
156 /* Initialize the passcode encoding/checking functions. */
160 * Don't do this again.
161 * Only the main thread instantiates and detaches instances,
162 * so this does not need mutex protection.
167 /* Verify ranges for those vars that are limited. */
168 if ((opt->chal_len < 5) || (opt->chal_len > OTP_MAX_CHALLENGE_LEN)) {
171 "invalid challenge_length, range 5-%d, using default of 6",
172 OTP_MAX_CHALLENGE_LEN);
175 /* Enforce a single "%" sequence, which must be "%s" */
176 p = strchr(opt->chal_prompt, '%');
177 if ((p == NULL) || (p != strrchr(opt->chal_prompt, '%')) ||
179 free(opt->chal_prompt);
180 opt->chal_prompt = strdup(OTP_CHALLENGE_PROMPT);
181 otp_log(OTP_LOG_ERR, "invalid challenge_prompt, using default of \"%s\"",
182 OTP_CHALLENGE_PROMPT);
185 if (opt->softfail < 0) {
187 otp_log(OTP_LOG_ERR, "softfail must be at least 1 "
188 "(or 0 == infinite), using default of 5");
191 if (opt->hardfail < 0) {
193 otp_log(OTP_LOG_ERR, "hardfail must be at least 1 "
194 "(or 0 == infinite), using default of 0");
197 if (!opt->hardfail && opt->hardfail <= opt->softfail) {
199 * This is noise if the admin leaves softfail alone, so it gets
200 * the default value of 5, and sets hardfail <= to that ... but
201 * in practice that will never happen. Anyway, it is easily
202 * overcome with a softfail setting of 0.
204 * This is because we can't tell the difference between a default
205 * [softfail] value and an admin-configured one.
207 otp_log(OTP_LOG_ERR, "hardfail (%d) is less than softfail (%d), "
208 "effectively disabling softfail",
209 opt->hardfail, opt->softfail);
212 if (opt->fast_sync && !opt->allow_sync) {
215 "fast_sync is yes, but allow_sync is no; disabling fast_sync");
218 if (!opt->allow_sync && !opt->allow_async) {
220 "at least one of {allow_async, allow_sync} must be set");
225 if ((opt->ewindow_size > OTP_MAX_EWINDOW_SIZE) ||
226 (opt->ewindow_size < 0)) {
227 opt->ewindow_size = 0;
228 otp_log(OTP_LOG_ERR, "max ewindow_size is %d, using default of 0",
229 OTP_MAX_EWINDOW_SIZE);
232 if (opt->rwindow_size && (opt->rwindow_size < opt->ewindow_size)) {
233 opt->rwindow_size = 0;
234 otp_log(OTP_LOG_ERR, "rwindow_size must be at least as large as "
235 "ewindow_size, using default of 0");
238 if (opt->rwindow_size && !opt->rwindow_delay) {
239 opt->rwindow_size = 0;
240 otp_log(OTP_LOG_ERR, "rwindow_size is non-zero, "
241 "but rwindow_delay is zero; disabling rwindow");
244 if ((opt->mschapv2_mppe_policy > 2) || (opt->mschapv2_mppe_policy < 0)) {
245 opt->mschapv2_mppe_policy = 2;
246 otp_log(OTP_LOG_ERR, "invalid value for mschapv2_mppe, using default of 2");
249 if ((opt->mschapv2_mppe_types > 2) || (opt->mschapv2_mppe_types < 0)) {
250 opt->mschapv2_mppe_types = 2;
252 "invalid value for mschapv2_mppe_bits, using default of 2");
255 if ((opt->mschap_mppe_policy > 2) || (opt->mschap_mppe_policy < 0)) {
256 opt->mschap_mppe_policy = 2;
257 otp_log(OTP_LOG_ERR, "invalid value for mschap_mppe, using default of 2");
260 if (opt->mschap_mppe_types != 2) {
261 opt->mschap_mppe_types = 2;
263 "invalid value for mschap_mppe_bits, using default of 2");
267 if (opt->twindow_max - opt->twindow_min > OTP_MAX_TWINDOW_SIZE) {
268 opt->twindow_min = opt->twindow_max = 0;
269 otp_log(OTP_LOG_ERR, "max time window size is %d, using default of 0",
270 OTP_MAX_TWINDOW_SIZE);
272 if ((opt->twindow_min > 0) || (opt->twindow_max < 0) ||
273 (opt->twindow_max < opt->twindow_min)) {
274 opt->twindow_min = opt->twindow_max = 0;
275 otp_log(OTP_LOG_ERR, "invalid values for time window, using default of 0");
279 /* Set the instance name (for use with authorize()) */
280 opt->name = cf_section_name2(conf);
282 opt->name = cf_section_name1(conf);
284 otp_log(OTP_LOG_CRIT, "no instance name (this can't happen)");
294 /* Generate a challenge to be presented to the user. */
296 otp_authorize(void *instance, REQUEST *request)
298 otp_option_t *inst = (otp_option_t *) instance;
300 char challenge[OTP_MAX_CHALLENGE_LEN + 1]; /* +1 for '\0' terminator */
303 int32_t sflags = 0; /* flags for state */
305 struct otp_pwe_cmp_t data = {
311 /* Early exit if Auth-Type != inst->name */
316 if ((vp = pairfind(request->config_items, PW_AUTHTYPE)) != NULL) {
318 if (strcmp(vp->vp_strvalue, inst->name))
319 return RLM_MODULE_NOOP;
323 /* The State attribute will be present if this is a response. */
324 if (pairfind(request->packet->vps, PW_STATE) != NULL) {
325 DEBUG("rlm_otp: autz: Found response to Access-Challenge");
326 return RLM_MODULE_OK;
329 /* User-Name attribute required. */
330 if (!request->username) {
331 otp_log(OTP_LOG_AUTH,
332 "autz: Attribute \"User-Name\" required for authentication.");
333 return RLM_MODULE_INVALID;
336 if ((data.pwattr = otp_pwe_present(request)) == 0) {
337 otp_log(OTP_LOG_AUTH, "autz: Attribute \"User-Password\" "
338 "or equivalent required for authentication.");
339 return RLM_MODULE_INVALID;
342 /* fast_sync mode (challenge only if requested) */
343 if (inst->fast_sync) {
344 if ((!otp_pwe_cmp(&data, inst->resync_req) &&
345 /* Set a bit indicating resync */ (sflags |= htonl(1))) ||
346 !otp_pwe_cmp(&data, inst->chal_req)) {
348 * Generate a challenge if requested. Note that we do this
349 * even if configuration doesn't allow async mode.
351 DEBUG("rlm_otp: autz: fast_sync challenge requested");
355 /* Otherwise, this is the token sync response. */
356 if (!auth_type_found)
357 pairadd(&request->config_items, pairmake("Auth-Type", "otp", T_OP_EQ));
358 return RLM_MODULE_OK;
361 } /* if (fast_sync && card supports sync mode) */
364 /* Set the resync bit by default if the user can't choose. */
365 if (!inst->fast_sync)
368 /* Generate a random challenge. */
369 if (otp_get_challenge(-1, challenge, inst->chal_len) == -1) {
370 otp_log(OTP_LOG_ERR, "autz: failed to obtain random challenge");
371 return RLM_MODULE_FAIL;
375 * Create the State attribute, which will be returned to us along with
376 * the response. We will need this to verify the response. It must
377 * be hmac protected to prevent insertion of arbitrary State by an
378 * inside attacker. If we won't actually use the State (server config
379 * doesn't allow async), we just use a trivial State. We always create
380 * at least a trivial State, so otp_authorize() can quickly pass on to
381 * otp_authenticate().
383 if (inst->allow_async) {
384 time_t now = time(NULL);
386 if (sizeof(now) != 4 || sizeof(long) != 4) {
387 otp_log(OTP_LOG_ERR, "autz: only ILP32 arch is supported");
388 return RLM_MODULE_FAIL;
392 if (otp_gen_state(&state, NULL, challenge, inst->chal_len, sflags,
393 now, hmac_key) != 0) {
394 otp_log(OTP_LOG_ERR, "autz: failed to generate state");
395 return RLM_MODULE_FAIL;
398 state = rad_malloc(5);
399 (void) sprintf(state, "0x00");
401 pairadd(&request->reply->vps, pairmake("State", state, T_OP_EQ));
404 /* Add the challenge to the reply. */
406 char *u_challenge; /* challenge with addt'l presentation text */
408 u_challenge = rad_malloc(strlen(inst->chal_prompt) +
409 OTP_MAX_CHALLENGE_LEN + 1);
411 (void) sprintf(u_challenge, inst->chal_prompt, challenge);
412 pairadd(&request->reply->vps,
413 pairmake("Reply-Message", u_challenge, T_OP_EQ));
418 * Mark the packet as an Access-Challenge packet.
419 * The server will take care of sending it to the user.
421 request->reply->code = PW_ACCESS_CHALLENGE;
422 DEBUG("rlm_otp: Sending Access-Challenge.");
424 /* TODO: support config-specific auth-type */
425 if (!auth_type_found)
426 pairadd(&request->config_items, pairmake("Auth-Type", "otp", T_OP_EQ));
427 return RLM_MODULE_HANDLED;
431 /* Verify the response entered by the user. */
433 otp_authenticate(void *instance, REQUEST *request)
435 otp_option_t *inst = (otp_option_t *) instance;
439 int resync = 0; /* resync flag for async mode */
441 unsigned char challenge[OTP_MAX_CHALLENGE_LEN]; /* cf. authorize() */
442 VALUE_PAIR *add_vps = NULL;
444 struct otp_pwe_cmp_t data = {
447 .returned_vps = &add_vps
450 /* User-Name attribute required. */
451 if (!request->username) {
452 otp_log(OTP_LOG_AUTH,
453 "auth: Attribute \"User-Name\" required for authentication.");
454 return RLM_MODULE_INVALID;
456 username = request->username->vp_strvalue;
458 if ((data.pwattr = otp_pwe_present(request)) == 0) {
459 otp_log(OTP_LOG_AUTH, "auth: Attribute \"User-Password\" "
460 "or equivalent required for authentication.");
461 return RLM_MODULE_INVALID;
464 /* Add a message to the auth log. */
465 pairadd(&request->packet->vps, pairmake("Module-Failure-Message",
466 OTP_MODULE_NAME, T_OP_EQ));
467 pairadd(&request->packet->vps, pairmake("Module-Success-Message",
468 OTP_MODULE_NAME, T_OP_EQ));
470 /* Retrieve the challenge (from State attribute). */
473 unsigned char *state;
474 int32_t sflags = 0; /* state flags */
475 int32_t then; /* state timestamp */
477 if ((vp = pairfind(request->packet->vps, PW_STATE)) != NULL) {
478 int e_length = inst->chal_len;
480 /* Extend expected length if state should have been protected. */
481 if (inst->allow_async)
482 e_length += 4 + 4 + 16; /* sflags + time + hmac */
484 if (vp->length != e_length) {
485 otp_log(OTP_LOG_AUTH, "auth: bad state for [%s]: length", username);
486 return RLM_MODULE_INVALID;
489 if (inst->allow_async) {
490 /* Verify the state. */
491 (void) memcpy(challenge, vp->vp_strvalue, inst->chal_len);
492 (void) memcpy(&sflags, vp->vp_strvalue + inst->chal_len, 4);
493 (void) memcpy(&then, vp->vp_strvalue + inst->chal_len + 4, 4);
494 if (otp_gen_state(NULL, &state, challenge, inst->chal_len,
495 sflags, then, hmac_key) != 0) {
496 otp_log(OTP_LOG_ERR, "auth: failed to generate state");
497 return RLM_MODULE_FAIL;
499 if (memcmp(state, vp->vp_strvalue, vp->length)) {
500 otp_log(OTP_LOG_AUTH, "auth: bad state for [%s]: hmac", username);
502 return RLM_MODULE_REJECT;
506 /* State is valid, but check expiry. */
508 if (time(NULL) - then > inst->chal_delay) {
509 otp_log(OTP_LOG_AUTH, "auth: bad state for [%s]: expired", username);
510 return RLM_MODULE_REJECT;
512 resync = ntohl(sflags) & 1;
513 } /* if (State should have been protected) */
514 } /* if (State present) */
518 rc = otprc2rlmrc(otp_pw_valid(username, challenge, NULL, resync, inst,
519 otp_pwe_cmp, &data, "auth"));
521 /* Handle any vps returned from otp_pwe_cmp(). */
522 if (rc == RLM_MODULE_OK) {
523 pairadd(&request->reply->vps, add_vps);
531 /* per-instance destruction */
533 otp_detach(void *instance)
535 otp_option_t *inst = (otp_option_t *) instance;
539 free(inst->chal_prompt);
540 free(inst->chal_req);
541 free(inst->resync_req);
544 * Only the main thread instantiates and detaches instances,
545 * so this does not need mutex protection.
547 if (--ninstance == 0)
548 memset(hmac_key, 0, sizeof(hmac_key));
555 * If the module needs to temporarily modify it's instantiation
556 * data, the type should be changed to RLM_TYPE_THREAD_UNSAFE.
557 * The server will then take care of ensuring that the module
558 * is single-threaded.
563 RLM_TYPE_THREAD_SAFE, /* type */
564 otp_instantiate, /* instantiation */
565 otp_detach, /* detach */
567 otp_authenticate, /* authentication */
568 otp_authorize, /* authorization */
569 NULL, /* preaccounting */
570 NULL, /* accounting */
571 NULL, /* checksimul */
572 NULL, /* pre-proxy */
573 NULL, /* post-proxy */